This is an experiment where the researcher manipulates one variable, and control/randomizes the rest of the variables. It has a control group, the subjects have been randomly assigned between the groups, and the researcher only tests one effect at a time.
The habitat is the kind of natural environment in which a particular organism species lives and it's ability to reproduce determines its niche.
(Prime Example):
Elephants shape their environment in many ways. They can change a forest to a grassy field or dig a hole that might become a pond.
<span>It took over 200 years for the "cell theory" to be formalized and accepted. Hooke and Leeuwenhoek were early microscopist's.... but at the time the nature of matter, the belief in spontaneous generation, and the idea there were little worlds within little worlds ad infinitinum was popular. The discovery of the periodic table and establishment that atoms were real, the demolishing of spontaneous generation, all happened at the time that Schwann and Schleiden (and others) were working with better microscopes, better ideas about the material world, and better observations...... thus the cell theory.
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Answer:
A plant cell is surrounded by rigid cell wall whereas animal cell does not have cell wall. Presence of a large vacuole in plant cell, which is small in animal cell. Plant cells are larger than animal cells. Plant cells have plastids whereas animal cells do not have plastids.
